Fig. 3.

CD4⁺ T-cell IL-2 secretion in response to PE38-derived peptide pools. Samples from 50 normal donors were stimulated with PE38-containing immunotoxin for 14 d and were restimulated with the overlapping peptides pools. Each pool was tested in quadruplicate, and SFC/1E6 cells were calculated. (A) Visual illustration of the strongest (black), weak (gray), and negative (white) responses. Donors were clustered using an automatic sorting based on the responsiveness of the pools. (B) Relative responses to 22 pools (n = 50).